Mean change from baseline in physical (PCS) and mental functions (MCS) of SF-36 [ Time Frame: Baseline (Day 1) and Day 169 ] [ Designated as safety issue: No ]

PCS=Physical Component Score

MCS=Mental Component Score

SF-36=Short Form 36

Proportion of subjects with at least one positive immunogenicity response [ Time Frame: Up to Day 169 ] [ Designated as safety issue: Yes ]

Proportion of subjects with adverse events (AEs), deaths, serious AEs, and AEs leading to discontinuation and proportion of laboratory marked abnormalities [ Time Frame: Up to Day 169 ] [ Designated as safety issue: Yes ]

Subjects at least 18 years of age who have a diagnosis of PsA by Classification Criteria for Psoriatic Arthritis (CASPAR)

Subjects have active PsA as shown by a minimum of ≥3 swollen joints and ≥3 tender joints (66/68 joint counts) at screening and randomization/Day 1 (prior to study drug administration). At least one of the swollen joints must be in the digit of the hand or foot

Subjects with at least one confirmed ≥2 cm target lesion of plaque psoriasis in a region of the body that can be evaluated excluding the axilla, genitals, groin, palms, and soles

Subjects must have had an inadequate response or intolerance to at least one non-biologic disease-modifying anti-rheumatic drug (DMARD)

Subjects may have been exposed to TNFi therapy. Subjects may have discontinued for any reason (inadequate response, intolerance or other)

Subjects may enroll on certain concomitant non-biologic DMARDs (Methotrexate, Leflunomide, Sulfasalazine, or Hydroxychloroquine) provided the medication has been used for at least 3 months with a stable dose for at least 28 days prior to randomization (Day 1)

If using oral corticosteroids (≤10 mg mg/day Prednisone equivalent), dose must be stable ≥14 days prior to randomization (Day 1)

Subjects may enroll on systemic retinoids (eg: Acitretin) provided the medication has been used for at least 3 months with a stable dose for at least 28 days prior to randomization (Day 1)

Exclusion Criteria:

Subjects with guttate, pustular, or erythrodermic psoriasis

Subjects who have had prior exposure to Abatacept (CTLA 4Ig) or other CTLA4 therapies

Subjects who have been exposed to any investigational drug within 4 weeks or 5 half lives, whichever is longer

Female subjects who had a breast cancer screening study that is suspicious for malignancy, and in whom the possibility of malignancy cannot be reasonably excluded following additional clinical, laboratory or other diagnostic evaluations

Subjects with a history of cancer within the last 5 years (other than non-melanoma skin cell cancers cured by local resection). Existing non-melanoma skin cell cancers must be removed prior to dosing. Subjects with carcinoma in situ, treated with definitive surgical intervention prior to study enrollment are allowed

Subjects with any bacterial infection within the last 60 days prior to screening (enrollment), unless treated and resolved with antibiotics, or any chronic bacterial infection (such as chronic pyelonephritis, osteomyelitis and bronchiectasis)

Subjects at risk for tuberculosis (TB). Specifically, subjects with:

Current clinical, radiographic or laboratory evidence of active TB

A history of active TB within the last 3 years even if it was treated

A history of active TB greater than 3 years ago unless there is documentation that the prior anti-TB treatment was appropriate in duration and type

Latent TB which was not successfully treated

Subjects with a positive TB screening test indicative of latent TB will not be eligible for the study unless they have no evidence of current TB on chest x-ray at screening and they are actively being treated for TB with isoniazid (INH) or other therapy for latent TB given according to local health authority guidelines (eg: Center for Disease Control). Treatment must have been given for at least 4 weeks prior to randomization (Day 1). These subjects should complete treatment according to local health authority guidelines

Subjects with herpes zoster that resolved less than 2 months prior to enrollment

Subjects with evidence (as measured by the investigator) of active or latent bacterial, active viral, or serious latent viral infections at the time of enrollment, including subjects with evidence of Immunodeficiency Virus (HIV) infection

Subjects who are not currently treated with a non-biologic DMARD and have clinical or radiographic evidence of arthritis mutilans (eg: digital telescoping or "pencil-in-cup" radiographic changes)

Subjects who have failed more than 2 TNFi due to inefficacy defined as inadequate response after 3 months treatment at a therapeutic dose

Subjects who have received TNFi therapy within 4 weeks for etanercept or within 8 weeks for adalimumab, certolizumab, infliximab, or golimumab

Subjects who have received prior use of apremilast within 4 weeks, ustekinumab within 20 weeks or briakinumab within 8 weeks

Subjects who have discontinued a non-biologic DMARD or systemic retinoid within four weeks or five half-lives, whichever is longer, prior to randomization (Day 1)

Use of any of the following within 28 days or five half lives whichever is longer prior to randomization (Day 1): Cyclosporine A, oral Tacrolimus, Mycophenolate Mofetil (MMF), Hydroxyurea, Fumaric Acid Esters, Paclitaxel, 6-Thioguanine, 6-Mercatopurine, or Tofacitinib

Contacts and Locations

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study.
To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below.
For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01860976